Comparison of Metal-Backed Free-Space and Open-Ended Coaxial Probe Techniques for the Dielectric Characterization of Aeronautical Composites.

Patricia López-Rodríguez,David Escot-Bocanegra,Frank Weinmann,David Poyatos-Martínez

doi:10.3390/s16070967

Patricia López-Rodríguez, David Escot-Bocanegra + Show 2 more

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https://doi.org/10.3390/s16070967

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Abstract

The trend in the last few decades is that current unmanned aerial vehicles are completely made of composite materials rather than metallic, such as carbon-fiber or fiberglass composites. From the electromagnetic point of view, this fact forces engineers and scientists to assess how these materials may affect their radar response or their electronics in terms of electromagnetic compatibility. In order to evaluate this, electromagnetic characterization of different composite materials has become a need. Several techniques exist to perform this characterization, all of them based on the utilization of different sensors for measuring different parameters. In this paper, an implementation of the metal-backed free-space technique, based on the employment of antenna probes, is utilized for the characterization of composite materials that belong to an actual drone. Their extracted properties are compared with those given by a commercial solution, an open-ended coaxial probe (OECP). The discrepancies found between both techniques along with a further evaluation of the methodologies, including measurements with a split-cavity resonator, conclude that the implemented free-space technique provides more reliable results for this kind of composites than the OECP technique.

Highlights

The study of the electromagnetic properties of composites has attracted much attention in the last decades with the aim of developing materials with an expected behaviour
The aim of this paper is to present such characterizations for several samples of composite materials that take part in an actual unmanned aerial vehicles (UAVs) fuselage utilized by the Spanish National Institute for Aerospace Technology (INTA), called SCRAB-II (manufactured by Sistemas de Control Remoto (SCR), Spain) [12]
In order to check the validity of the metal-backed free-space methodology for fiberglass composites, the reference materials are measured with both approaches, free-space and the commercial solution (OECP)

Summary

Introduction

The study of the electromagnetic properties of composites has attracted much attention in the last decades with the aim of developing materials with an expected behaviour. Considering that the properties of a composite material are related to the properties and the amount of its constituents, the trend is to develop materials with customized characteristics to be used for certain purposes. Their prediction out of the composite constituents is a long-standing problem, which has not yet been completely solved, and, interest in experimentally characterizing composite. Some new generation fuselages and wings are designed to be almost fully composite providing lighter and more fuel-efficient aircraft, like current unmanned aerial vehicles (UAVs)

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